1. Field of the Invention
The present invention relates to a castor and, more particularly, to a castor for a chair and the like.
2. Description of the Related Art
A conventional castor in accordance with the prior art shown in FIGS. 6 and 7 comprises a main body 1, two rollers 10 each rotatably mounted on the main body 1 and each having an inside formed with a locking slot 12, and a control member 11 pivotally mounted on the main body 1 and provided with a locking rod 13 movable in the locking slot 12 of each of the two rollers 10.
In operation, when the control member 11 is located at the position as shown in FIG. 6, the locking rod 13 of the control member 11 is located at the lower end of the locking slot 12 of each of the two rollers 10, so that the two rollers 10 are rotatable freely, and the castor is movable on the ground. On the contrary, when the control member 11 is located at the position as shown in FIG. 7, the locking rod 13 of the control member 11 is located at the upper end of the locking slot 12 of each of the two rollers 10, so that the two rollers 10 are locked by the locking rod 13 of the control member 11, and the castor cannot be moved on the ground.
However, when the two rollers 10 are locked by the locking rod 13 of the control member 11, the two rollers 10 are still rested on the ground, so that the castor easily slips on the ground by applying a pulling force on the castor, thereby causing inconvenience to the user. In addition, the locking rod 13 of the control member 11 rubs the locking slot 12 of each of the two rollers 10 frequently, so that the locking rod 13 of the control member 11 and the wall of the locking slot 12 of each of the two rollers 10 are easily worn out during a long-term utilization, thereby decreasing the locking effect of the castor.